等效的字符串包含在 google bigquery

Question

我有一张如下图所示的表格

我想创建two new binary columns，表明主题是否有steroids 和aspirin。我希望在Postgresql and google bigquery 中实现这一点

我尝试了以下方法，但它不起作用

select subject_id
case when lower(drug) like ('%cortisol%','%cortisone%','%dexamethasone%') 
then 1 else 0 end as steroids,
case when lower(drug) like ('%peptide%','%paracetamol%') 
then 1 else 0 end as aspirin,
from db.Team01.Table_1


SELECT 
db.Team01.Table_1.drug
FROM `table_1`,
UNNEST(table_1.drug) drug
WHERE REGEXP_CONTAINS( db.Team01.Table_1.drug,r'%cortisol%','%cortisone%','%dexamethasone%')

我希望我的输出如下所示

Answer 1

以下是 BigQuery 标准 SQL

#standardSQL
SELECT 
  subject_id,
  SUM(CASE WHEN REGEXP_CONTAINS(LOWER(drug), r'cortisol|cortisone|dexamethasone') THEN 1 ELSE 0 END) AS steroids,
  SUM(CASE WHEN REGEXP_CONTAINS(LOWER(drug), r'peptide|paracetamol') THEN 1 ELSE 0 END) AS aspirin
FROM `db.Team01.Table_1`
GROUP BY subject_id   

如果适用于您问题的样本数据 - 结果是

Row subject_id  steroids    aspirin  
1   1           3           1    
2   2           1           1     

注意：我使用的是LIKE on steroids，而不是简单的 LIKE 以冗长和冗余的文本结尾 - 这是REGEXP_CONTAINS

Answer 2

在 Postgres 中，我建议使用 filter 子句：

select subject_id,
       count(*) filter (where lower(drug) ~ 'cortisol|cortisone|dexamethasone') as steroids,
       count(*) filter (where lower(drug) ~ 'peptide|paracetamol') as aspirin,
from db.Team01.Table_1
group by subject_id;

在 BigQuery 中，我会推荐 countif()：

select subject_id,
       countif(regexp_contains(drug, 'cortisol|cortisone|dexamethasone') as steroids,
       countif(drug ~ ' 'peptide|paracetamol') as aspirin,
from db.Team01.Table_1
group by subject_id;

您可以使用sum(case when . . . end) 作为更通用的方法。但是，每个数据库都有一种更“本地”的方式来表达这种逻辑。顺便说一句，FILTER 子句是标准 SQL，只是没有被广泛采用。

Answer 3

使用条件聚合。这是一个适用于大多数（如果不是全部）RDBMS 的解决方案：

SELECT
    subject_id,
    MAX(CASE WHEN drug IN ('cortisol', 'cortisone', 'dexamethasone') THEN 1 END) steroids,
    MAX(CASE WHEN drug IN ('peptide', 'paracetamol') THEN 1 END) aspirin
FROM db.Team01.Table_1.drug
GROUP BY subject_id

注意：不清楚您为什么使用LIKE，因为您似乎有完全匹配；我将LIKE 条件变为等式。

Answer 4

你错过了group-by

select subject_id,
    sum(case when lower(drug) in ('cortisol','cortisone','dexamethasone')
       then 1 else 0 end) as steroids,
    sum(case when lower(drug) in ('peptide','paracetamol') 
       then 1 else 0 end) as aspirin
from db.Team01.Table_1
group by subject_id

使用like关键字

select subject_id,
 sum(case when lower(drug) like '%cortisol%'
        or lower(drug) like '%cortisone%'
        or lower(drug) like '%dexamethasone%'   
    then 1 else 0 end) as steroids,
    sum(case when lower(drug) like '%peptide%'
        or lower(drug) like '%paracetamol%'
    then 1 else 0 end) as aspirin
from db.Team01.Table_1
group by subject_id

Answer 5

另一个可能更直观的解决方案是使用BigQuery Contains_Substr 返回布尔结果。